Electric cut-out



March 19, 1929.

c. w. F'LORl NG 1,706,150

ELECTRIC CUT-OUT Filed July 12, 1926 94-fi 511,9 tot Patented Mar. 19, 1929.

UNITED STATES 1,706,150 PATENT. OFFICE.

CARL W. FLORING, OF NEW YORK, N. Y., ASSIGNOB TO GENERAL ELECTRIC COM- PANY, A CORPORATION OF NEW YORK.

nnnc'rnic CUT-OUT.

Application filed July 12,

My invention relates to that type of cut outs commonly called Edison base cut outs.

An object of the invention is to make it impossible to use a jumper or coin for short circuiting the metal screw shell with the metal centre contact of a socket or receptacle by displacing any metal path for the current after a plug has bl o wn; another object of the invention is to apply same to present day devices such as are termed main line and branch cut outs; another object of the invention is to shift the additional first cost of the device somewhat towards the decreased second cost of the fuse plugs used with my device, in combination with suitable and reliable contacting means to bring about the desired results.

In .the drawings which accompany and form part of the specification, Figure 1 represents a longitudinal sectional view of my cut out on the broken line 11 of Fig. 2.

Fig. 2 is a plan view of the same, the window structure being omitted.

Fig. 3 is a plan view of the plug shell. prior to assemblage.

Fig. 4 is a detail side view looking toward Fig. 2 from arrow 4.

Referring now more specifically to the drawings, 2-indicates a receptacle or socket of any suitable insulating material preferably molded out of porcelain, and having in its well a metal center contact 3. the active head or end of which is depressed in a pit 23 surrounding which and spaced from it is an annular groove or pit 25. This socket carries preferably rigidly fixed therein or thereto a metal screw shell 4.

Mounted stationarily in said socket 2 is an insulating tubular barrier member 5 of any suitable construction or design and interposed between the center contact 3- and the screw shell 4. This member of insulation 5 is illustrated as being ofshell-like form substantially co-extensive with the socket screw shell 4 and fitted adjacent the inner surface thereof by any suitable means, thereby effectively insulating the shell 4 from any possible contact leading toward it directly from the center contact aforesaid;

The numeral 7 indicates a plug body of hollow cup shape construction as usual and adapted to project into the socket structure aforesaid, carrying with it a center contact 8 projectable into the pit 23 and against the contact 3. Also surrounding the lower or inner end of the plug 7 is a rim 24 adapted to fit 1926. Serial No. 122,052.

with a close but slidable fit into the annular pit or groove 25. Fitted to and carried by the plug body of insulation 7 is a metal screw shell connector 9 of generally cylindrical forni but whose top outside portion, as shown best in Fig. 3, comprises an inwardly directed flange or flange sections 14 between each two of which is a metal tongue,,two of-which are indicated at 13, and another at 15, which are adapted to be bent upward in line with the body and the shell and thence inward again severally over shoulders 12 formed at the bottom of notches 10 and 11 formed in the crown or top portion of the shell 7. The tongue 15 is bent into V or groove formation to receive the outer end of the fuse link 17 wherein it may be fixed in any convenient manner as by soldering, squeezing, or the like. The connection 15 with its grooved structure to receive the link 17 is seated in the assemblage of the construction in a notch 6 and rests inward against a shoulder structure 19. The flange members 14 are thus brought and held snugly against the bottom surface of the head extension or shoulder of the plug 7 making a rigid and reliable connection between the in sulation of the plug and its screw shell 9.

The top central portion of the plug 7 is recessed to receive a closure member 21 which may be transparent or otherwise asdesired, but shown as held in place by suitable means such as a ring 20 or any other holding means within or below the top surface of the plug. ,The link 17 leads to and is secured in any suitable or conventional manner as by soldering to the center contact 8 of the plug. The shell 9 may have any desired relation to the socket shell 4, but is shown fitted upon the outside of the shell 4 for the usual purpose of making electrical connection between the two shells and so between the center contacts and the socket shell through the link 17.

lVithout unnecessary limitation of relation between the contacts 3 and 8, either of which might be located in a pit, while the other projects into the pit, I show that the contact 8 projects into the pit for cont-act with the socket contact 3. Among the reasons for this construction is to prevent the dangerous practice of inserting a metal connector of an unauthorized capacity in the event that the safety link 17 becomes blown. It is a common and dangerous practice to insert a bit of metal such as a penny into the socket whose edge or end in the usual socket makes contact with the cleanly through the strip of .cause,. first, the ends or socket shell, while the center contact of the socket completes the circuit through such piece of metal. In this construction the penny introduced into the socketwould vfail to make a circuit because it would not reach the center contact 3 because of the pit 23 nor by any reason could its periphery or edge reach either of the shells 4t and 9 becauseof the interposition of the special insulating barrier member 5 between center contacts. Another common practice for making a temporary cut out connection is to interpose a strip or ribbon of thin metal such as tin foil into the socket, but this attempt would fail with this construction beedges of the ribbon would be gripped by the co-operation of the flange 24 and pit 25 and so caused to be drawn taut or stretched across the center pit. The center contact projecting toward and intended to enter the center pit would then shear ribbon or metal and so cause the contact to fail'even though a portion of the tin foil or metal ribbon might be extended over the sleeve or insulating member 5 so as to reach the screw shells. This would be true irrespective of whether the contact 3 is in a pit or the-contact 8 might be located in a pit in the plug 7. The insulating portions if made of porcelain may readily be molded with sharp edges as at 26 to insure the clean shearing or cutting of the dummy. contact or connector indicated at 22, and correspondingly the contact 8 may have sharp cutting edges 27 for co-operation with the edges 26.

I claim:

1."In a cut out, the combination of a rethe screw shells and the rounding and spaced from said body to freely telescope outside said tubular barrier of the receptacle.

2. In a cut out, the combination of a receptacle having a well in the bottom of which "center and screw shell contacts are mounted and a relatively thin tubular barrier extending outwardly'from the bottom of said well within and in proximity to said screw shell, and a plug having a cup-shaped body adapted to telescope within said barrier, said body having a center contact mounted in its lower end wall and anchored thereto a screw shell contact surrounding and spaced from said body to freely telescope outside of said barrier and a fusible element extendin through the chamber of said cup-shaped fiody and electrically connectin the center and screw shell contacts thereo 3. A cut-out receptacle having center and screw shell contacts in the well thereof and provided with an annular pit in the bottom of said well concentric with said screw shell contact, and a plug body having center and screw shell contacts and provided at its lower end with an annular crown flange adapted to enter said pit when the plug is screwed home in the receptacle.

CARL W. FLORING.- 

